Cardiac Biomarkers

About the Test

Cardiac biomarkers are substances that are released into the bloodstream when heart muscle is damaged or stressed. Cardiac biomarkers help healthcare providers know if symptoms are due to a heart attack (myocardial infarction), angina, heart failure or another problem.

Increases in cardiac enzymes can also indicate acute coronary syndrome (ACS) or myocardial ischemia.

Treatments for these conditions vary. An accurate diagnosis is critical to ensuring you receive the appropriate care.

There are different types of cardiac biomarkers. All of them are enzymes or proteins. Elevated heart enzymes may show that you have cardiovascular disease or other heart problems.

Current cardiac biomarker tests that may be used to help diagnose, evaluate, and monitor individuals suspected of having acute coronary syndrome (ACS) include:

• Troponin (I or T)—this is the most commonly ordered and most specific of the cardiac markers. It is elevated (positive) within a few hours of heart damage and remains elevated for up to two weeks. Rising levels in a series of troponin tests performed over several hours can help diagnose a heart attack.
  
  

• Creatinine kinase MB. This is a subtype of creatinine kinase. It is more sensitive for finding heart damage from a heart attack. CK-MB rises 4 to 6 hours after a heart attack. But it is generally back to normal in a day or two. Because of this, it's not helpful when a healthcare provider is trying to figure out if your recent chest pain was a heart attack.
  
  

Other biomarker tests that may be used include:

• hs-CRP — this test may be used to help determine risk of future heart attacks in people who have already suffered one in the past.
  
  

• BNP (or NT-proBNP) — although usually used to recognize heart failure, an increased level in people with ACS indicates an increased risk of recurrent events.
  
  

• Homocysteine is an amino acid that is typically present in very small amounts in all cells of the body. Elevated homocysteine may be related to a higher risk for coronary heart disease, stroke, peripheral vascular disease (fatty deposits in peripheral arteries), and hardening of the arteries (atherosclerosis). High levels of homocysteine increase the risk of blood clot formation in vessels and may lead to heart attack and stroke.

What’s the purpose of cardiac biomarkers?

Healthcare providers measure cardiac marker levels to:

• Screen for heart damage and other problems.

• Diagnose heart conditions that cause symptoms such as chest pain, angina and shortness of breath.

• Monitor how well heart medications and heart surgery work.